Large Errors from Assuming Equivalent DC and High-Frequency Electrical Characteristics in Metal–Multiple-Insulator–Metal Diodes

Metal–insulator–metal (MIM) tunnel diodes are essential for ultra-high-speed rectification. We review an erroneous method for distributing DC voltage drops across multiple insulator layers that is used in all the published literature on these devices. It has resulted in large errors between designed and fabricated multi-insulator diodes. For multi-insulator MIM diodes, voltage division is dependent on both tunneling resistances and oxide capacitances. We demonstrate that correct voltage division at DC is determined by the rectification resistance, as opposed to the commonly used capacitive voltage division. We find that DC characteristics of multi-insulator diodes cannot be used to predict high-frequency behavior.